This invention relates to fuse pullers for installing or pulling fuses. More specifically, this invention relates to fuse pullers having one portion for installing or pulling cylindrical fuses and, alternatively, another end for installing or pulling blade fuses.
A fuse is a type of circuit breaker in an electrical circuit. A fuse "breaks" the circuit, i.e., stops the flow of electrical current in the circuit, when a level of current flows through the circuit that exceeds the ceiling for current flow allowed by the fuse. In one type of popular fuse, a cylindrical automative fuse for example, a wire in the fuse burns out and breaks the circuit through the fuse when the current exceeds the wire's maximum current flow capacity.
After such a fuse burns out and breaks the circuit, the circuit will not operate until the fuse is replaced. The old fuse must be removed and new fuse installed.
In automotive applications in particular, the fuses are often located in a difficult-to-reach location, such as under the dashboard or in even more remote locations. The fuses are also frequently mounted in parallel, very close together, and in a recessed or semi-recessed area in a small fuse box. The object is to protect the fuses from inadvertent contact with occupants or contaminants (such as water splashing up from the car floor) while allowing access when needed and intended for installation and replacement when necessary.
While this type of mounting does provide essential protection for both the fuses and the occupants, it frequently renders both removal and installation of a fuse a remarkably frustrating task. Frequently, the human hand simply cannot reach into the cramped space between the fuse and the fuse box or between adjacent fuses where not separated by a fuse box wall. In addition, it is dangerous to try to remove the fuses by grasping them with bare hands, since there is always the risk of electrical shock if the hands make contact with the opposing fuse clamps for the fuse.
These same types of concerns with blade-type fuses. Blade fuses usually have a flattened body blade with a protruding ridge on one side of the blade and two prongs extended from the other in the plane of the body.
Several tools exist in the prior art for removing and/or installing one or both of these types of fuses. One tool used to remove the cylindrical fuses is a screwdriver with an insulated handle. The screwdriver blade is inserted into the area of cylindrical fuse to pry it loose from the two clamps retaining it in the fuse box at each end of the fuse. This tool rises breaking the glass intermediate section of the fuse, making further removal of the broken pieces very difficult. It also risks breakage to other fuses in the vicinity of the fuse being removed.
Another prior art tool has a small plastic body with two sets of resilient arms extending in different directions from the body. One set of arms is designed to clamp the periphery of a blade type fuse, and the other the cylindrical periphery of the cylindrical fuse. The arms for the blade fuse grasp the blade securely by grasping the protruding ridge on the side of the blade fuse body opposite the fuse blades. The arms for the cylindrical fuse do not clamp the cylindrical fuse as securely, however, because the cylindrical surface is more difficult to grasp with the level of clamping force provided by the resilient arms alone.